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Date:   Fri, 20 Aug 2021 00:04:12 +0200
From:   Pali =?utf-8?B?Um9ow6Fy?= <pali@kernel.org>
To:     Kari Argillander <kari.argillander@gmail.com>
Cc:     linux-fsdevel@vger.kernel.org,
        linux-ntfs-dev@lists.sourceforge.net, linux-cifs@vger.kernel.org,
        jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Jan Kara <jack@suse.cz>,
        OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
        "Theodore Y . Ts'o" <tytso@mit.edu>,
        Luis de Bethencourt <luisbg@kernel.org>,
        Salah Triki <salah.triki@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Dave Kleikamp <shaggy@kernel.org>,
        Anton Altaparmakov <anton@tuxera.com>,
        Pavel Machek <pavel@ucw.cz>,
        Marek =?utf-8?B?QmVow7pu?= <marek.behun@nic.cz>,
        Christoph Hellwig <hch@infradead.org>
Subject: Re: [RFC PATCH 05/20] ntfs: Undeprecate iocharset= mount option
Message-ID: <20210819220412.jicwnrevzi6s25ee@pali>
References: <20210808162453.1653-1-pali@kernel.org>
 <20210808162453.1653-6-pali@kernel.org>
 <20210819012108.3isqi4t6rmd5fd5x@kari-VirtualBox>
 <20210819081222.vnvxfrtqctfev6xu@pali>
 <20210819102342.6ps7lowpuomyqcdk@kari-VirtualBox>
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On Thursday 19 August 2021 13:23:42 Kari Argillander wrote:
> On Thu, Aug 19, 2021 at 10:12:22AM +0200, Pali Rohár wrote:
> > On Thursday 19 August 2021 04:21:08 Kari Argillander wrote:
> > > On Sun, Aug 08, 2021 at 06:24:38PM +0200, Pali Rohár wrote:
> > > > Other fs drivers are using iocharset= mount option for specifying charset.
> > > > So mark iocharset= mount option as preferred and deprecate nls= mount
> > > > option.
> > >  
> > > One idea is also make this change to fs/fc_parser.c and then when we
> > > want we can drop support from all filesystem same time. This way we
> > > can get more deprecated code off the fs drivers. Draw back is that
> > > then every filesstem has this deprecated nls= option if it support
> > > iocharsets option. But that should imo be ok.
> > 
> > Beware that iocharset= is required only for fs which store filenames in
> > some specific encoding (in this case extension to UTF-16). For fs which
> > store filenames in raw bytes this option should not be parsed at all.
> 
> Yeah of course. I was thinking that what we do is that if key is nls=
> we change key to iocharset, print deprecated and then send it to driver
> parser as usual. This way driver parser will never know that user
> specifie nls= because it just get iocharset. But this is probebly too
> fancy way to think simple problem. Just idea. 

This has an issue that when you use nls= option for e.g. ext4 fs then
kernel starts reporting that nls= for ext4 is deprecated. But there is
no nls= option and neither iocharset= option for ext4. So kernel should
not start reporting such warnings for ext4.

> > Therefore I'm not sure if this parsing should be in global
> > fs/fc_parser.c file...
>